1. Field of the Invention
The field of the invention pertains to cables used in electronic audio frequency systems. More specifically it pertains to audio cables with predictable, musically relevant, and beneficial mechanical resonances for use with microphonic or vibrationally-sensitive equipment, and process with repeatable results for making same.
2. Description of the Prior Art
The widespread use of the telegraph initiated the need for the discovery of many of the electrical parameters used in audio cable design, and the radio and the telephone supplied the impetus for the rest. And while these electrical parameters are of known significance, it will be shown that other parameters are also of significance in a musical culture where microphonic or vibrationally-sensitive equipment such as vacuum tube electronics play such a vital role.
The electronics era was ushered in with the inventions of the vacuum tube and radio. Vacuum tube driven public address systems followed shortly, and were in turn soon followed by other amplified devices such as the electric guitar. The later development of the transistor enabled electronics to become much smaller, lighter, and produce much less heat than their (vacuum) tube counterparts. The transistor also converted less vibrational energy into signal energy than the tube. These differences in size, weight, heat, and microphonics respectively almost caused the tube to disappear from use in the western world.
However, the last decade of the twentieth century saw a resurgence in the use of tube electronics. Despite these obvious technological shortcomings, a significant portion of amateur and professional recording engineers, musicians, and listeners use and prefer the sound of tube electronics.
During the transitional period between the tube and the transistor, a small number of recording engineers and record producers retained some of their tube signal processing electronics instead of trading them in on the transistorized versions that became available in the 1970""s. They kept and used these tube products because they sounded more natural; the tube sound had a warmth and smoothness that wasn""t available from transistorized equipment. Their work became so well regarded that others started copying their methods, and these others too became widely copied.
Because of this, the tube has made a spectacular comeback and vintage tube electronics are today expensive, high-status items found in every major recording studio. Tubes are an accepted symbiotic companion to the almost universal use of digital recording, processing, and playback equipment. The recent advent of relatively inexpensive digital signal processors and recorders has turned a specialized trend for vintage tube electronics into a general trend that also covers modern tube products, and extends down to the smallest home recording set-up.
The same comeback has occurred with a significant number of home listeners. They feel that music has a more natural and xe2x80x9cmusicalxe2x80x9d quality when vintage and some modern tube components are used in their audio systems. Similarly, many guitarists feel that their instruments sound more natural and have a greater responsiveness when used with tube amplifiers or pre-amplifiers.
Many modern tube products are available, for home and professional use, in all price ranges up to a hundred thousand dollars or more. The tube renaissance seems unstoppable. Some companies that opposed the trend several years ago have publicly changed their stance and reintroduced tube products they stopped making 25 or more years ago.
The vibration-sensitivity of a musical instrument is understood. It is well known that each and every part, from the largest to the smallest, has resonances that combine to make up that instrument""s sound. This is paralleled in tube equipment because of the tube""s microphonic nature. Instead of being impervious to vibrations, a tube will convert some percentage of the vibrational energy to which it is subjected into an AC voltage, which is added to the signal it is passing. It is also well known to those in the field that every tube is microphonic to one degree or another, and that they often become more microphonic as they age.
While the vibration-sensitivity of a musical instrument is taken into account during its construction, the vibration-sensitivity of a tube is usually ignored. Electronics using tubes cannot help but be as sensitive as musical instruments to the materials and techniques of construction. However, the same microphonic characteristic that causes the situation can be used for benefit.
Musical instruments have many avenues for tonal improvement after leaving the factory; musicians constantly buy products on a hunt for better and better tone. There are many aftermarket manufacturers of reeds, mouthpieces, strings, pickups, and bridges, etc., all constructed from differing materials with added embellishments, and all for the improvement of an instrument""s tone. Since tube electronics are vibration-sensitive like musical instruments, they can also have their resonance signature modified after leaving the factory. Obvious ways include clamping or attaching resonators directly to the chassis of a tube product.
However, there are other, less obvious methods that allow the modification of the resonance signature of vibration-sensitive/microphonic equipment such as, but not limited to, tube products. The following example is given to illustrate the fact that while the remoteness of a set of resonances may seem at first glance to negate its ability to effect tone, these resonances are in fact a significant contributor to overall tonal quality.
It is common knowledge to those in the field that the degree of tension in a musician""s arm and shoulder muscles has a significant effect on an instrument""s tone. A reduction of muscle tenseness will mellow not only the musician but also the tone produced by an instrument. The resonant energy of the strings passes through the bow-hair, through the wood of the bow, and into the musician. This energy is filtered by the resonances in the bow-hair, the wood of the bow, and the combination of the mass and spring-rate of the musculature of the arms and shoulders, and coupled back into the instrument where it adds to the resulting tonality.
Some of these effects of external resonances on a musical instrument also find a parallel with tube or other microphonic or vibrationally-sensitive equipment. The flexibility of input and output cables is not a barrier to most transverse or longitudinal vibrations. In fact, connecting cables are direct paths for external vibrational energy. They are solidly and mechanically coupled to a rigid chassis that provides little or nothing to stop vibrations from being conducted directly to microphonic tube elements. The energy conducted through these cables is sufficient to significantly affect the tone of tube equipment. This situation has an analogy in the energy conducted through a bow after having interacted with the muscles of a musician.
Electrical parameters have heretofore been the primary focal point when designing audio cables. In fact, in almost all cases, with the exception of wear resistance issues, electrical parameters have been the only focal point.
There have been many examples of serious and well meaning attempts to further the art of audio cable design. A belief that conductor quality is the key to xe2x80x9cbetterxe2x80x9d sound has caused some designers to use copper of ever increasing purity and price, even though the actual reduction in resistance is vanishingly small. Other designers use exotic materials in sophisticated configurations to solve xe2x80x9cproblemsxe2x80x9d caused by the xe2x80x9cskin effect,xe2x80x9d which has to do with the increasing resistance of conductors at very high frequencies, and frequency-dependent velocity differences in the speed of the signal. In actuality, at audio frequencies these xe2x80x9cproblemsxe2x80x9d are inaudible. These exotic cable designs can be very expensive and cost as much as one thousand dollars per foot.
Unfortunately, in many real world systems these cable designs sound different from one another. Therefore some aspect of the electrical design or the physical realization of that cable must be responsible for this. However, the electrical design parameters as given are incapable of generating sufficient audible differences at audio frequencies. This leaves the physical realization of the cable.
Because cables must have mechanical resonances, and microphonic or vibrationally-sensitive equipment will be affected by these resonances, ignoring these resonances will be detrimental to a large number of listeners, recording engineers, and musicians in their quest for better sound and tonal quality. In many situations it is the mechanical aspect of an audio cable, rather than its electrical design, that is responsible for that cable""s sound.
Not only are the mechanical aspects important, but ignoring a seemingly unimportant variable in the construction of an audio cable can render its sonic outcome unpredictable, and its use for a particular musical situation unacceptable.
The prior art of audio cables has primarily been confined to concerns over electrical parameters.
Several prior art audio signal cables have emphasized frequency dependent timing issues in their design: U.S. Pat. No. 4,538,023 to Brisson discloses the use of different gauge wires of different lengths are used to increase signal integrity, and U.S. Pat. No. 4,767,890 to Magnan discloses the use of multiples of several very small gauges of wire are used in parallel to effect an all xe2x80x9cskinxe2x80x9d conductor.
Another example is U.S. Pat. No. 4,628,151 to Cardas discloses the use of a specific conductor size distribution is proposed for maximum efficiency of electrical signal transfer.
Another example, U.S. Pat. No, 5,929,374 to Garland discloses the reduction of dielectric absorption in the insulating medium between the conductors and to cancel vibrations set up in the conductors caused by signal passage.
Each given example of the prior art has been concerned with electrical parameters. Only one example has a portion of its design related to mechanical resonances. U.S. Pat. No. 5,929,374 includes an approach that seeks to minimize conductor-to-conductor resonances. At the same time it also introduces multiple sources of other mechanical resonances as part of this design. It""s use of equal length blocks of balsa wood as insulators in a regularly spaced fashion may as claimed break up longitudinal resonances through the insulator. However, it also couples many multiples of the same series of high frequency balsa wood resonances into the conductors. The conductors then act as a conduit for this energy, coupling it directly into the equipment used with this cable.
When used with microphonic or vibrationally-sensitive electronics or transducers, the mechanical resonances from the balsa wood will in some instances be perceived as beneficial, and in others, detrimental to the sound quality. The construction of this cable will do little to keep external resonant energy from exciting the internal cable components; nor will its construction keep external energy or excited internal resonances from coupling into the equipment it is used with.
The other given examples of the prior art have claimed that their particular solutions involving a cable""s electrical parameters infuse their cable designs with superior results. However, under real world conditions, no single cable design has been able to eliminate its competition. It is well known to those knowledgeable in the field that each design has its fervent supporters, its detractors, and those in between. This occurs because in any one given audio system of one type, a single cable design will often sound superior to all others. However, a fundamental problem exists because this same cable design will clearly sound inferior in another system of the same type.
Often this variability can be explained by the fact that many home and professional audio systems prefer and use tube components that are microphonic and thus vibrationally-sensitive. This makes many real world systems dependent on a favorable balance of resonances, both acoustic and mechanical. While room acoustics are reasonably well understood and sometimes taken into account, the impact of the mechanical resonances of the cable are little understood and rarely even considered.
The prior art has limitations in that each cable has its own unique and inherent xe2x80x9cneutralxe2x80x9d sounding cable is desirable, it will have to include sophistication in both its electrical and mechanical design components. In addition, for musical situations where a beneficial tonal character would have merit, a process for creating a cable with this specific tonality would be highly useful and beneficial.
There is no prior technology concerning audio cables having predictable, beneficial, and musically relevant mechanical resonances intended for use with microphonic or vibrationally-sensitive electronics or transducers. This is a problem previously undiscovered in the prior art and the need for such cables and a process with repeatable results to address this issue is realized by the present invention.
In view of the foregoing disadvantages inherent in the known types of audio cables now present in the prior art, the present invention provides an improved audio cable with musically relevant mechanical resonances and process for making same, and overcomes the above-mentioned disadvantages and drawbacks of the prior art. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved audio cable with musically relevant mechanical resonances and process for making same and method which has all the advantages of the prior art mentioned heretofore and many novel features that result in an audio cable with musically relevant mechanical resonances and process for making same which is not anticipated, rendered obvious, suggested, or even implied by the prior art, either alone or in any combination thereof.
It is therefore an object of the present invention is to create audio cables with a musically relevant xe2x80x9csoundxe2x80x9d especially for use with microphonic or vibrationally-sensitive equipment. The process with repeatable results disclosed does not ignore electrical requirements, but brings into proper prominence the sonic contributions of the mechanical resonances from the cable""s materials, and especially those from its construction.
A conventional audio cable is essentially homogeneous from one end to the other in between its connectors or bare ends. This can be mechanically modeled as a single spring of a given length, mass, and spring-rate (compliance). The audio cables of the present invention are created in a process that results in a mechanical model that is much more complex, and yet predictable. This new model consists of a series of many different springs with multiple lengths, masses, and compliances. This xe2x80x9cpartitioningxe2x80x9d of a single spring into a series of multiple and different springs is the focal point of the present invention, and creates a more complex and variable resonant signature. This signature can be designed and crafted to benefit many varied musical situations.
A further object of the present invention is to provide different sounding cables for different applications. As the musical situation changes, so do the tonal requirements. A cable with a warm sound, when used in an already warm sounding system will not contribute to signal clarity when that is the tonal preference. A cable with accentuated highs and a lack of warmth will help to balance the system""s warm sound, resulting in increased signal clarity. This and many other tonal styles are possible through use of the process of the present invention.
Yet another object of the present invention is to provide the ability to predict the sonic outcome of the material selection and construction process. When the results of every step in the design and construction process, no matter how small, are understood in terms of their mechanical resonances, prediction becomes possible. Without this understanding, the results are variable.
Yet still another object of the present invention is to provide the ability to repeat the sonic characteristics of a successful audio cable prototype. As with prediction, the mechanical resonances of the materials and construction process must be understood. Otherwise it becomes difficult, except in serendipitous occurrences, to duplicate successful cable sonics.
Another object of the present invention is to provide the ability to fine tune the sound of an audio cable without complete disassembly of the cable. As it obviously takes longer to completely disassemble a cable than it does to only partially disassemble it, the cost of manufacture will be decreased through methods disclosed in the present invention. Additionally, in hand-made products a certain variability will occur. The ability to fine tune the cable will increase the production yield.
A still further object of the present invention is to provide the ability for common materials to be used to build a xe2x80x9csuperiorxe2x80x9d cable. Common belief is that expensive materials are required to build a superior audio cable. However, it is a well known and confusing fact that at times expensive cables will actually make an audio system sound worse. This is the result of the prevailing focus only on electrical parameters and the cost of the materials, rather than the actual sonic results from using that cable. A results oriented approach must consider both the electrical and the mechanical.
Through use of material selection, partitioning of the length of the cable into discrete sections having beneficial mechanical resonances, and by creating other musically relevant resonances through manipulation of the necessities of construction, a superior sounding audio cable can be created using common and inexpensive materials.
Yet another object of the present invention is to create xe2x80x9cneutralxe2x80x9d sounding cables. Prior art audio cables are overly uniform in a mechanical sense, and develop only a few strong resonances. When used with microphonic or vibrationally-sensitive equipment, these too few resonances stand out and significantly color the sound of that equipment. A xe2x80x9cneutralxe2x80x9d sounding cable must have an even distribution of mechanical resonances throughout the audio spectrum. When an audio cable is built in this fashion, the contributions from the resonances are continuous and less overt; no sonic areas stand out to cause coloration of the sound. This is possible through use of the process of the present invention.
Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, two embodiments of the present invention are disclosed.
Vibrational energy from a musical instrument, either from the instrument itself or from speakers powered by one or more amplifiers whose signal source is either live or recorded, excite the materials and partitions of the present invention. These resonances are directly coupled into, and add their audio frequency energy to that of the host device. This added energy is an important contributor to the tonal quality, or lack thereof, of many performances, recordings, and other musical situations.
In the case of a vibrationally-sensitive musical instrument, the mechanical resonant energy of the audio cable of the present invention is added to that of the instrument, which influences the vibrations of its strings. These string vibrations are in turn converted to electrical energy by that instrument""s pick-up.
In the case of microphonic or vibrationally-sensitive passive devices such as but not limited to microphones, the externally excited resonant energy of the audio cable of the present invention is coupled into these devices and is added to its electrical output signal.
In the case of microphonic or vibrationally-sensitive active electronics such as but not limited to those using tubes, the resonant energy of the audio cables of the present invention is coupled into these electronics and added to the electrical signal passing through them.
The mechanical resonance signature of the present invention is a sum of the resonances contributed by all of its parts: the multiple partitions and their various masses and compliances, the connectors, the insulating and decorative coverings, and all other construction necessities such as informational labels.
The present invention""s conductors, whether single or multiple, are selected to resonate in a chosen range of the audio spectrum. These conductors are then divided through predictable and mechanical means into multiple independently resonating sections in order to create other beneficial and musically relevant resonances. These mechanical means include compliance, mass, and hinge-point differentiation of one section from another.
The resonances created by the process and methods used in the audio cable of the present invention""s construction are more important to this cable""s sound than any other mechanical or electrical parameter. A process with repeatable results for constructing multiples of a successful sonic design for a specified musical situation is disclosed and is based on an in depth understanding of the mechanical ramifications of the construction process.
These together with other objects of the invention, along with the various features of novelty that characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.